Topic summary
Follow-up: Reconciling a label claim with a content assay
This is a generated summary. It shows the 5 most-liked posts from a topic of 31, in their original order, with the accepted answer included where one exists. It is a reading aid and it will miss nuance — the full topic is the record.
Thank you for the correction. I have edited my earlier post with a note rather than silently, so the thread still makes sense to read. The error was mine and it was the kind that comes from remembering a figure instead of looking it up.
26 likes 3mo
a.eriksen, post #5: Practical note that does not fit anywhere else. Whatever you conclude from this topic, write down what you did and when. The single most useful thing in your own records is not any individual result; it is that they are dated and consecutive. Go to post
For anyone arriving from a search: the marked solution above is the direct answer, and the replies underneath it add the caveats that make it safe to use.
t.ibarra, post #3: When a document puts the specification in the result column, it has told you the release criterion, not the measurement. Those are different claims and the second is weaker. Go to post
Picking up post #25: that is the part I would want checked first.
When method identifiers are missing: "reversed-phase HPLC" is less specific than "reversed-phase HPLC at 214 nm on a C18 column with a 10 to 40% acetonitrile gradient over 20 minutes". The second lets someone reproduce the analysis. The first does not.
m.stephanopoulos, post #22: post #21 is right about the mechanism and I think understates the practical bit. Purity and content are different measurements: purity tells you what proportion of the detected material is the intended species. Content tells you how much of the intended species is present in the container. A lyophilised vial can be 99% pure and contain… Go to post
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Worth separating two things that post #25 runs together.
Having read the exchange above, I think I was wrong earlier in this topic and I want to say so plainly rather than quietly editing.
The correction was fair and I had been repeating something I had not checked carefully enough.
Read the full topic (31 posts)
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